Shielding device

ABSTRACT

A shielding device with a shielding component ( 17 ) forming a shield surface, a heat shield in particular, has a clamping component ( 1 ) which is formed to be integral with the shielding component ( 17 ) by means of an extension of such component which is folded onto itself at a bending point ( 29 ) in such a way that two clamping legs ( 31, 33 ) positioned side by side are formed the clamping surfaces of which facing each other delimit between themselves a clamping gap ( 35 ) with one end closed at the bending point ( 29 ).

The invention relates to a shielding device having a shielding component forming a shielding surface, a heat shield in particular, and a clamping component.

Shielding components which may be fastened on a mounting component serving as support have been disclosed. Such shielding devices are widely used in automotive engineering in order to protect heat-sensitive structural components such as sensors, fuel lines, pressure cells, critical bolted joints on sensitive housing components, etc. While the heat generated, for example, by an economical performance-optimized diesel engine on the cylinder or crankcase housing may be very slight, this is not at all true of “hot zones” such as those of manifolds, turbochargers, catalytic converters, etc., so that protective shielding surfaces must be present at appropriate points. This applies in particular in the vicinity of catalytic converters, which represent strong heat sources because of their phases of high surface temperature.

During operation the shielding devices required in the “hot zones” are subjected not only to thermal loads but to mechanical loads as well, especially as a result of vibrations which are transmitted to the shielding component involved by way of support components. Because of these stresses special requirements are set for the connecting devices which hold such shielding devices in place on the associated mounting components. The conventional state-of-the-art connecting devices provide springs (clips) which are clamped under a certain amount of preliminary tension to stay bolts or the like, but also to entire structural components such as ignition switches of generators or exhaust manifolds. The clamping force or retaining force is determined by selection of the spring material and the structural configuration of the respective springs. It has been found that, in particular if the support component involved is a high-temperature component, the danger exists that fatigue phenomena may occur in the material of the spring and is increased if vibrations resulting from operation are added. Consequently, connecting devices of the prior art do not ensure reliable fastening of the respective shielding components.

In view of the foregoing the object of the invention is to provide by a simple and reliable method a shielding device the design of which ensures especially secure fastening of the shielding component even when subjected to high continuous thermal and mechanical loads.

It is claimed for the invention that this object is attained by a shielding device having the characteristics specified in claim 1 in its entirety.

The distinguishing feature of the invention is represented by the fact that a clamping component which forms the connecting device for fastening the shielding component to a support component is an extension of the shielding component and is integral with this component. This extension is such that, if it is folded back on itself, two clamping legs are formed which by clamping surfaces facing each other form between themselves a clamping gap having a closed end at the bending point. The clamping component thus forms an integral part of the shielding component, so that a connecting device of especially high structural strength is formed. Reliable mounting of the shielding device is accordingly ensured even in the presence of high thermal and mechanical loads.

By preference the dimensions of the clamping component are such that the length of the clamping leg as measured from the bending point to its free end spaced a distance from this point corresponds approximately to the primary extent of the shielding component measured in this direction. Clamping surfaces of large dimensions are accordingly made available for operation in conjunction with mounting components of correspondingly great dimensions.

In especially advantageous exemplary embodiments there is associated with the clamp legs a tensioning device by means of which the clamping surfaces may be pressed against a mounting component present in the clamping gap. As a result, a high clamping force is maintained over long periods of operation, since the risk is avoided of weakening of the force of application as a result of material fatigue such as results from decrease of the force of the springs in conventional clips.

By special preference there may be provided as tensioning device a bolt nut on the outside of a clamping leg and in alignment with it screw holes for a clamp bolt in the clamping legs, this making it possible to achieve high clamping force with a simple and compact design.

In advantageous exemplary embodiments the configuration may be such that the shield surface has a primary surface component and a secondary surface component which is bent at an angle or arched in relation to it, the extension forming the clamping leg being adjacent to the secondary surface component. In a configuration such as this, in addition to a main shielding zone there is available between it and the clamping component another shielding zone which, in keeping with the circumstances, may follow a pattern different from that of the primary shielding zone and may require positioning of the clamping component as desired a certain distance from the shielding component.

For this purpose the configuration may be such that the primary surface component is on the whole rectangular in outline and adjoins the secondary surface component on a long side of the primary surface component.

As regards the width of the secondary surface component, it may in effect form an extension of the shorter side edges of the primary surface component or the width of the secondary surface component as measured in the direction the clamping leg may be less than the length of the clamping legs, which in this instance extend beyond the side edges of the secondary surface component on both sides. In this configuration, in consideration of the thermal shielding effect the primary surface component may be large enough so that it is sufficiently great in area while the secondary surface component may be narrower in shape yet meet the mechanical requirements set for adequate structural strength.

Especially high structural strength is obtained for the shielding device as a whole if at least one reinforcing seam is formed which extends over the shielding component and the clamping component in their entirety.

It is especially advantageous for the configuration to be such that two reinforcing seams positioned symmetrically with the shielding surface of the shielding component are provided which extend perpendicularly to the longitudinal direction of the clamping leg and in parallel with each other to the remote end of the clamping element.

The invention will be described in detail below with reference to exemplary embodiments presented in the drawing, in which, in diagrammatic form not drawn to scale,

FIG. 1 presents a perspective diagonal view of the top of an exemplary embodiment of the shielding device claimed for the invention, components of the associated tensioning device being omitted;

FIG. 2 a perspective diagonal view of the exemplary embodiment of FIG. 1, viewed from the bottom;

FIG. 3 a detached perspective diagonal view on a smaller scale than in FIGS. 1 and 2, a view in which the exemplary embodiment is shown when installed, that is, fastened on a support component;

FIG. 4 a perspective diagonal view similar to that of FIG. 1 of a second exemplary embodiment of the shielding component; and

FIG. 5 a view similar to that of FIG. 3 showing the exemplary embodiment of FIG. 4 in the installed state.

FIG. 3 shows the exemplary embodiment presented in FIGS. 1 and 2 as installed, the shielding device with its clamping component 1 being fastened on a mounting component 3 serving as support. The latter is in the form of a sheet metal component with a curved end section in the center of which is a longitudinal slot 5. The other end section slot, of the mounting component having no slot 3 forms a fastening plate 7 fastened by screws to an exhaust manifold 9 of an internal combustion engine. The exhaust manifold 9 and catalytic converter 11 form a “hot zone” so that it is necessary to provide thermal shielding for heat-sensitive zones of an adjacent housing component 13. In the example illustrated in FIG. 3 there are on the housing component 13 heat-sensitive screws 15 which are shielded by the shielding component 17 forming a shielding surface serving as a heat shield.

FIGS. 1 and 2 illustrate the shielding device in detail. As is to be seen, the device is a one-piece structural component, clamping component 1 and shielding component 17 being formed from a single sheet of metal such as stainless steel so as to be integral. The plate component has been cut and molded in such a way that the shielding component 17 forms a primary shield surface 19 and an adjoining secondary shield surface 21 bent to form an obtuse angle. The clamping component 1 in turn adjoins the latter. As is to be seen in FIGS. 1 and 3 in particular, the primary shield surface 19 is more or less rectangular in outline (aside from the rounded edge areas) and the secondary surface component 21 adjoins a longer side of the primary surface component 19. As is distinctly to be seen in FIG. 1 in particular, the side edges 23 of the secondary surface component 21 form a direct extension of the shorter side edges 25 of the primary surface component 19. Clamping component 1, in turn, which forms an integral extension of the shielding component 17, adjoins the end of the secondary surface component 21 remote from the primary surface component 19, the width of the transitional area being reduced by constrictions 27 in the transitional area between secondary surface component 21 and clamping component 1.

The clamping component 1 adjoining the constrictions 27 extends in a plane essentially in parallel with the plane of the primary surface component 19. The sheet-metal batch forming the clamping component 1 is cut to form blanks in such a way that the blanks are bent at an angle at a bending point 29 which extends essentially in parallel with the adjacent side edge 25 of the primary surface component 19 and so may be folded over so that the clamping component 1 forms two adjacent clamping legs 31 and 33, the clamping surfaces facing each other defining a clamping gap 35 which is closed at the bending point 29 and open at the opposite end 37 so that a support component such as the mounting component 3 shown in FIG. 3 may be introduced into the clamping gap 35 from the open end 37.

As is also clearly to be seen in FIGS. 1 and 2, the length of the clamping gap 35 as measured from the bending point 29 to the open end 37 corresponds essentially to the length of the shielding component 17 measured in the same direction, and accordingly both to the length of its primary surface component 19 and to that of its secondary surface component 21. The width of the clamping component 1 measured transversely to the dimension of the primary surface component 19 measured more or less in this direction, that is, essentially transversely to the length of its side edges 25. Clamping surfaces of correspondingly great dimensions for positioning on the mounting component 3 are accordingly obtained for the clamping gap 35. As FIG. 2 shows, there is on the exterior of the clamping leg 33 a nut 39 to be used in conjunction with screw holes 43 (FIG. 1) in the clamping legs 31 and 33 and with a tensioning bolt 41 (FIG. 3) to form a tensioning device for bracing the clamping component 1 on the mounting component 3. In the example illustrated in FIGS. 1 to 3, there being a longitudinal slot 5 in the mounting component 3, the tensioning device is mounted so as to be essentially in the center of the clamping component 1.

The sheet-metal component is provided with reinforcing seams 45 in order to increase the structural strength of the shielding device. These seams extend, spaced a certain distance from each other, perpendicularly to direction of the length of the clamping gap 35 and in parallel with each other both over the shielding component 17 and over the adjoining clamping leg 31 of the clamping component 1 to the clear end edge of the latter. As is to be seen in FIG. 1 in particular, the reinforcing seams 45 extend in symmetrical configuration in relation to the primary surface component 19 and secondary surface component 21 and on both sides of the screw holes 43 of the clamping component 1.

The second exemplary embodiment shown in FIGS. 4 and 5 differs essentially in two respects from the example first described. This applies firstly to the position of the tensioning device made up of nut 39, tensioning bolt 41 (FIG. 5), and screw holes 43. Unlike FIGS. 1 to 3, the tensioning device is positioned not in the central area of the clamping component 1 but very near the open end 37 of the clamping gap 35. This positioning of the tensioning device is provided for fastening the shielding device on a mounting component having no longitudinal slot or having another suitable opening for passage of tensioning bolt 41. In other respects the clamping component 1 corresponds from the viewpoint of its configuration to the clamping component described in the foregoing.

The shielding component 17 of the example illustrated in FIGS. 4 and 5, just as is the case with the example described in the foregoing, is divided into a primary surface component 19 and a secondary surface component 21. The second essential difference of the second exemplary embodiment is that the secondary surface component 21 is of a width, as measured in the direction of the clamping gap 35, significantly smaller than that of the clamping component 1 or the primary surface component 19 measured in the same direction. In addition, the secondary surface component 21 is in the form of a structural component which is arched, relatively long, and curved in comparison to the primary surface component 19. The shape and dimensions selected for it are such that, in addition to the primary shielding zone in the form of the primary surface component 19, a second shielding zone is formed which is of the length and extent desired and/or extends over an optionally greater distance between the shielding component 17 and mounting component 3. In other respects, as regards the configuration of the clamping component 1 and primary surface components 19 of the shielding component 17, including the positioning of reinforcing seams 45, the second exemplary embodiment corresponds to the example described in the foregoing. 

1. A shielding device with a shielding component (17) forming a shield surface, a heat shield in particular, and a clamping component (1) which is formed to be integral with the shielding component (17) by means of an extension of such component which is folded onto itself at a bending point (29) in such a way that two clamping legs (31, 33) positioned side by side are formed the clamping surfaces of which facing each other delimit between themselves a clamping gap (35) with one end closed at the bending point (29).
 2. The shielding device as claimed in claim 1, wherein the length of the clamping legs (31, 33) as measured from the bending point (29) to a free end (37) spaced a distance from this bending point (29) corresponds approximately to the main extent of the shielding component (17) measured in this direction.
 3. The shielding device as claimed in claim 1 or 2, wherein there is associated with the clamping legs (31, 33) a clamping device (39, 41, 43) by means of which the clamping surfaces may be pressed against a mounting component (3) positioned in the clamping gap (35).
 4. The shielding device as claimed in claim 3, wherein the tensioning device has at least one nut (39) present on the exterior of a clamping leg (33) and screw holes (43) in alignment with the clamping leg (39) for a tensioning bolt (41) in the clamping legs (31, 33).
 5. The shielding device as claimed in claim 4, wherein a nut (39) and associated screw holes (43) are positioned approximately half way over the length of the clamping legs (31, 33).
 6. The shielding device as claimed in claim 4, wherein a nut (39) and associated screw holes (43) are positioned in the vicinity of the free end of the clamping legs (31, 33).
 7. The shielding device as claimed in one of claims 1 to 6, wherein the shield surface has a primary surface component (19) and a secondary surface component (21) which is bent at an angle to the primary surface component (19) or is arched and wherein the extension forming the clamping legs (31, 33) is adjacent to the secondary surface component (21).
 8. The shielding device as claimed in claim 7, wherein the primary surface component (19) is more or less rectangular in outline and wherein the secondary surface component (21) adjoins a long side of the primary surface component (19).
 9. The shielding device as claimed in claim 8, wherein the side edges (23) of the secondary surface component (21) extend approximately in parallel with each other and vertically in relation to the longitudinal direction of the clamping legs (31, 33).
 10. The shielding device as claimed in claim 9, wherein the width of the secondary surface component (21) as measured lengthwise on the clamping legs (31, 32) is smaller than the length of the clamping legs (31, 33), which extend on both sides beyond the side edges (23) of the secondary surface component (21).
 11. The shielding device as claimed in one of claims 1 to 10, wherein at least one reinforcing seam (45) is present which extends over the shielding component (17) and the clamping component (1).
 12. The shielding device as claimed in claim 11, wherein two reinforcing seams (45) symmetrically positioned to the shield surface of the shielding component (17) are provided which extend to the remotely positioned end of the clamping component (1) vertically in relation to the longitudinal direction of the clamping legs (31, 33) and in parallel with each other.
 13. The shielding device as claimed in one of claims 8 to 12, wherein the width of the clamping legs (31, 33) as measured perpendicularly to the length of such clamping legs (31, 33) is at least one-half as great as the length of the shorter side (25) of the primary surface component (19) of the shielding surface (17). 